The Halki Theological School on an island off Istanbul was closed in 1971 by Turkish authorities in a huge blow to the spiritual heart of Orthodoxy. Without the seminary, the Orthodox are denied a center for theological study and clerical training in what was the ancient Byzantine capital.

Some fear this could one day leave them without an Istanbul-based patriarch, who is considered the ''first among equals'' in the world's Eastern Orthodox hierarchy.

The present ecumenical patriarch, Bartholomew I, has said often the school's fate rests ''in the Lord's hands.'' But now a different type savior could now be sweeping in from the West: the European Union.

Turkey's ambition to join the EU has forced profound reforms mandated by Brussels, including abolishing the death penalty last year. On June 19, the Turkish parliament passed human rights changes that give more freedoms to minority Kurds, who were once discouraged from even giving their children Kurdish names.

An EU statement June 20 praised the reforms as a ''clear sign'' of Turkey's EU effort. Turkey hopes to start membership talks with the EU in 2005, but claims it could be ready next year.

Bartholomew and others cautiously hope the pro-EU tide could wash aside the restrictions on Halki and other rules on patriarch succession which some Orthodox leaders claim were imposed to cement Turkish control on the few thousand ethnic Greeks left in Istanbul.

''I think to join the EU ... such limits are not acceptable within the European mentality,'' Bartholomew said in early June.

For both sides, however, the issues run much deeper than just the patriarch's modest domain in Istanbul. The tradition, stability and even survival of the faith are often raised.

To the world's 200 million Orthodox, Halki is a tangible connection to the Byzantine Empire that ruled for more than 1,000 years until Constantinople fell to Ottoman Muslims in 1453 and became Istanbul.

The school once a key seminary for Orthodox leaders including Bartholomew was opened in 1844 on the site of a ninth century monastery. In 1971, the Turkish government shut the seminary college under a law requiring state control for all higher education involved in religious and military training. While there are other Orthodox seminaries around the world, none can match Halki's stature.

Turkey had already held sway over the Orthodox world for decades: a 1923 rule established that all ecumenical patriarchs must be Turkish citizens. That was the condition for allowing the patriarchate to remain in Istanbul under the Treaty of Lausanne, which also opened the way for a massive exchange of ethnic populations between Greece and Turkey.

The once vast ethnic Greek population in Istanbul and Turkey's Aegean coast began to evaporate. Today, less than 5,000 remain leaving just a handful of Turkish-born Orthodox clerics able to someday succeed the 63-year-old Bartholomew.

''At this rate, if nothing changes, our options for future patriarchs could be very, very, very limited,'' said the head of the Greek Orthodox Church in South America, Metropolitan Tarasios, who worked as an aide to Bartholomew for more than a decade. ''Who's going to be left?''

In Turkey, however, any issue involving religion is extremely sensitive and could butt against EU demands for greater openness.

The firmly secular republic that succeeded the Ottoman Empire in 1923 has unwavering support from nearly all military and political leaders in the overwhelmingly Muslim country.

Women are barred from wearing Islamic head scarves in schools and government offices. Compulsory primary school education was extended to eight years in part to limit the reach of private, Islamic-oriented high schools. No independent religious schools are allowed for higher degrees which forced the closure of the Orthodox school on Halki, or Heybeli in Turkish.

The patriarch's status is also caught in Turkey's ongoing battles between secular leaders and religious traditions.

Some officials strongly object to any reference to the patriarch as ''ecumenical'' meaning global or universal or loosening the requirements that he be a Turkish citizen. They worry such moves could weaken Turkish influence over the faith.

''The Turkish state doesn't want to hear the word 'ecumenical' uttered,'' said Baskin Oran, a political science professor at Ankara University in Turkey's capital.

A Turkish parliament member, Onur Oymen, said amending the religious education rules for the Orthodox could open the door for Islamic fundamentalists and other groups to seek the same privileges.

''Laws prohibit private high-level religious schools. There isn't a single Muslim university in Turkey,'' he said. ''It doesn't have anything to do with (being) Christian or Muslim.''

But Greece's foreign minister, George Papandreou, said reopening Halki has been part of EU accession discussions. Greece has put aside its long-standing animosity toward Turkey to become its main EU sponsor in a bid for greater regional security.

''I hope Turkey sees (Halki) as one more bridge between itself and Europe,'' said Papandreou, ''and therefore a vital interest.''